https://bugs.freedesktop.org/show_bug.cgi?id=75128
--- Comment #4 from Michel Dänzer michel@daenzer.net --- (In reply to comment #3)
- I've already restarted kdm as the artifacts make it impossible to read the
screen and 2) for whatever reason my screenprint (ksnaphot) stopped working and I've been unable to determine why or how to fix it.
There are many other tools for taking screenshots, or you could take a picture with a mobile phone or digital camera.
Without seeing a picture, 'artifacts in the form of dialog boxes appear and won't go away' sounds more likely to be an issue with some KDE component than with the drivers FWIW. What does xwininfo say when you click on a dialog box?